Metformin Plus Paclitaxel for Metastatic or Recurrent Head and Neck Cancer (METTAX)

• Disease control at week 12 [ Time Frame: 12th week ] [ Designated as safety issue: No ]
  Number of subjects at week 12 with complete response, partial response or stable disease, over the total number of subjects, for each arm. Disease control means complete response, partial response or stable disease, according to RECIST 1.1.
  
  

• Progression-free survival [ Time Frame: 6mo after the last patient recruited ] [ Designated as safety issue: No ]
  We will measure the number of subjects without progressive disease (complete response, partial response or stable disease) 6mo after the start of therapy, also after 1 and 2 years from the start of therapy. PFS will also be analysed with log-rank test, and reported as HR with respective 95% CI and p value, and median PFS will be estimated with kaplan-meyer method. All calculations will be performed 6 months after the last patient recruited. Also, the survival rate at year one and two will be calculated.
  
  
• Overall Survival (subjects without death (any cause)) [ Time Frame: 6mo after the last enrolled patient ] [ Designated as safety issue: No ]
  We will measure the number of subjects without death (any cause) 6mo after the start of therapy, and also after 1 and 2 years from the start of therapy. OS will also be analysed with log-rank test, and reported as HR with respective 95% CI and p value, and median OS will be estimated with kaplan-meyer method. All calculations will be performed 6 months after the last patient recruited. Also, the survival rate at year one and two will be calculated.
  
  
• Number of patients with Grade 3-5 Adverse Events in each arm, for each category of AE [ Time Frame: 6 mo after the last enrolled patients ] [ Designated as safety issue: Yes ]
  Safety and tolerability will be assessed using NCI CTCAE v3. The number of patients in each arm experiencing grade 3-5 AE (for each AE) over the total number of subjects will be measured, and the proportion of patients experiencing AE in each arm will be compared using uncorrected chi-sq test. AE will be recorded in baseline and in each visit, and the worst grade AE will be considered.
  
  

METTAX is a phase II randomized trial that aim to evaluate the addition of metformin to paclitaxel in patients that failed to curative-intent treatment for Head-and neck neoplasms.

Patients eligible for this protocol will be randomized to paclitaxel 175mg/m2 plus metformin or placebo until disease progression or unacceptable toxicity. The primary end-point is disease control (complete response, partial response or stable disease, according to RECIST 1.1) in the 12th week. Secondary end-points are PFS, OS, response rate and safety. Molecular markers in samples collected before and under treatment will be tested for correlation with clinical outcomes.